Effect of manganese on structure and catalytic properties of fe-zeolite catalysts for the synthesis of hydrocarbons from CO and H/sub 2/

Phase composition and structure of Fe-zeolite and Fe-Mn-zeolite catalysts have been investigated by x-ray diffraction and Moessbauer spectroscopy. Catalytic activity and selectivity of these catalysts for the synthesis of hydrocarbons from CO and H/sub 2/ have been studied. The activity of the Mn-containing catalyst is considerably lower, but its selectivity toward the lower olefins, C/sub 2/-C/sub 4/, improved as compared with the Fe-zeolite catalyst. The effect of the Mn on activity and selectivity was related to a diminished reduction of the Fe oxides to metal and to a lower degree of conversion of the latter to carbides in the course of the hydrocarbon synthesis.